Modern vehicles continue to evolve to more complex machines requiring more complex technology to diagnose problems within the vehicle. Modern vehicles are run by onboard computers that receive signals from a large array of sensors and provide signals to an array of actuators that control the functioning of the vehicle. A failure in the sensors, actuators, the onboard computer or the connections between the various components can lead to a vehicle malfunction.
Many vehicle malfunctions may not be evident to the driver, since they affect only the smog control devices, the efficiency of the engine, or long term maintenance items. Even when the driver is aware of a problem with the vehicle, the driver often cannot determine the severity of the problem. For example, when an oil problem is detected and displayed by illuminating a light on the vehicle console, the driver cannot determine if the vehicle is out of oil or the oil sensor has failed. In older vehicles, the driver could at least check the “dip stick” to determine if there was oil in the oil reservoir in the engine. However, some newer cars have even done away with this mechanical aid.
Many problems can only be diagnosed by connecting a scanner to the vehicle through a wiring harness. While all scanners have certain generic functions, the most useful information requires a scanner that is individualized to the particular manufacturer. Even if an individual had a scanner for her vehicle, the expertise and cost needed to connect and utilize the scanner is beyond the capability of the vast majority of vehicle operators.
The problems inherent in detecting and diagnosing potential vehicle failures are further complicated by the rise of self-service gas stations. When gasoline was dispensed by an attendant, the attendant at least checked some of the fluid levels and tire inflation. Today, this function is left to the driver who seldom checks such items when he or she is filling the vehicle's fuel tank. Other problems include the need to become informed of current manufacture's recalls or warranty issues and to create a maintenance history for a car to improve the potential future diagnostic capabilities.